Application to textiles of dinitro compounds



Patented June 1934 APPLICATION TO TEXTILES OF DINITRO COMPOUNDS Donald H. Powers, Moorestown, N. J assignor to Riihm & Haas Company, Philadelphia, Pa.

No Drawing. Application February 13, 1932,

Serial No. 592,850 I 8 Claims.

This application relates to materials highly suitable, in their application to textiles, as reduction preventers in kier boiling and resist printing. They are also very efficient in pre- 5 venting haloing and scratching-.

It is common knowledge that the anthraquinone or vat type of dyestuffs are rendered soluble by reducing them to the leuco form in the presence of an alkaline medium. This converlfl sion to the soluble form is necessary in the printing of vat colors. However, there are cases in which it is desirable to prevent this reduction. Well known examples are in resist printing under vat colors and preventing mark offs in kier boiling. In resist printing, a substance is printed on the fabric which prevents the yat color, which is printed on top of it, from penetrating into the fabric. A compound which prevents the reduction of the vat color will prevent the penetration of the vat colors. While vat colors are rendered more soluble by reducing them in an alkaline medium, it is also true that sulphur colors and basic colors are frequently reduced to facilitate their application to fabrics and it is equally true that these compounds preventing reduction mayprevent the application of sulphur, basic or other reducible dyestuffs.

Heretofore substances such as nitro benzene sulphonic acid and nitro toluene sulphonic acid in dilute alkali solution and phenolic compounds capable of developing a quinoid structure in alkaline solution have been used to prevent marking off; and sodium mono-nitro benzenesulphonate has been used for resist printing in conjunction with a methyl ether of cellulose under vat colors.

.I have found that the di-nitro aryl derivatives are much more effective than any of the compounds previously' described. In preventing "40 marking off they appear to be extremely effective. It is also possible to make up a resist printing paste with very low concentrations of the di-nitro compound, which may be easily applied. They have been found to be from fifty to seventy-five percent more effective than any of the compounds previously described.

Di-nitro benzenesulfonic acids are extremely powerful reduction preventers. The water soluble or water dispersible salts of these acids prevent the reduction of the vat color due to the fact that they use up the hydrosulphite or sulfoxylate. By water soluble is meant soluble to at least of 1% in aqueous solution or dilute alkali solution. The term is used in this sense throughout the application. The sulfonic' acid,

carboxylic acid or phenol group is present to make the compound water soluble or alkali soluble. Extremely low percentage of sodium dinitro benzenesulfonate entirely prevent marking off in kier boiling and also prevent the printing of vat colors.

I have also found that these substances are also extremely effective in preventing scratching and haloing. In vat discharge printing on fabrics dyed with direct, developed or other dischargeable colors, trouble is frequently encountered with haloing and scratching. The haloing is due to the fact that the excess hydrosulphite in the vat print paste creeps out i into the fabric around the print, causing haloing. The scratching is due to the fact that a very small amount of the hydrosulphite print paste gets under the doctor blade onto the face of the fabric, causing a white scratch. where the ground color is destroyed. If the fab- 7 ric dyed with a dischargeable color is treated with a very weak solution of sodium di-nitro -chlor phenolate, -benzenesulphonate, or -benzoate before printing, and this solution dried into the cloth, this treated fabric will not shown haloes 30 or scratches due to the fact that the small amount of di-nitro in the fabrics destroys the small amount of hydrosulphite which might cause haloing or scratching. Other substances of the grouping described above will produce similar results.

In discharge printing with vat colors, difiiculty frequently arises from facing. The entire face of the cloth is dulled by the deposit of a very. thin film of the hydrosulphite-vat-printing 0 paste as it goesthrou'gh the printing machine.

This very thin film of hydrosulphite destroys or dulls slightly the color on the face of the fabric. Treating this fabric with sodium di-nitro benzene-sulfonate prior to printing prevents this 9 facing.

I have also found that when the warp threads of a fabric are treated with sodium di-nitro ben- -zenesulfonate, and this fabric printed with vat colors in the regular manner, the resulting print 0 resembles a shadow print due to the fact that the warp threads have not been printed by the vat dyestuff but only the. filling threads. Some very pleasant and unique effects may be obtained by this process. The sodium di-nitro benzenesulfonate may be applied to the warp threads when they are sized prior to weaving. The sodiumdi-nitro benzenesulfonate is mixed up with the sizing material, such as potato starch, and dissolved in water and the warp sized with the di-nitro benzenesulfonate-starch mixture in the slasher in the regular manner. Examples of these processes are as follows:

Example 1In kier boiling to prevent marking ofli-Two thousand pounds of unbleached cotton goods containing a woven vat dyed stripe are boiled in a kier for 8 hours at 10 pounds pressure in a 4% solution of caustic soda containing 2% of sodium, 2, 4 dinitro benzencsulfonate. The goods are soured, washed, bleached in chemic of 2-3 Tw., soured, washed and dried. The vat stripe has not marked oiI on the white cloth due to the protective action of the di-nitro benzenesulfonate.

Example 2-Resist printing.Printing paste is made up as follows-800 parts of thickener, 200 parts of sodium 2,4-dinitro benzoate mixed up to a resist printing paste. The thickener consists of 40 parts of corn dextrine and 100 parts of water, heated to boil, stirred until smooth. The fabric is printed with this paste, dried, and subsequently padded through an alkaline hydrosulphite solution of a reduced vat color such as tetra-prom indigotin (Color Index No. 1184) The sodium 2,4 dinitro benzoate in the resist paste destroys the hydrosulphite which comes in contact with it in the padding solution, preventing the dyeing or printing of the vat color in the spots where the resist occurs.

Example 3A sample of cotton or rayon fabric is dyed with a 2% solution of pontamine diazo black B. H. concentrated (Color Index No. 401) This fabric is then padded through a of 1% solution of sodium 3,5-dinitro salicylate and dried. This fabric is then discharge printed in the usual fashion with vat colors. The presence of the sodium 3,5 di-nitro salicylate prevents scratching and haloing.

Example 4.Warp yarns are run through a slasher box containing a mixture of potato starch and 10% sodium 2,4.- di-nitro phenolate. This paste is then dried into the warps on drycans and the warps woven into piece goods in the regular fashion. These piece goods when printed with any vat colors reduced with hydrosulphite or sulfoxylate resist the penetration of the vat colors into the warp yarns.

Example 5.-Fabrics containing vat dyed yarns to be mercerized are run on a mercerizing frame through 25% sodium hydroxide solution containing 2% sodium, 2,4-dinitro phenyl acetate, at 20 C. The cloth should be traveling at approximately a speed of 60 yards a minute so that it is in the alkaline mercerizing liquor for approximately 30 seconds before the first wash. The caustic is neutralized in the usual manner with 3% sulphuric acid, rinsed in water and dried.

While the sodium salts are mentioned specifically experiments prove that all other water soluble di-nitro aryl derivatives produce the same results to some degree. In the preferred form of the invention the potassium salts are interchangeable withthe sodium salts. In the case of dinitro sulphonic acid derivatives the calcium and barium salts are also soluble and give good results.

I have found that the following compounds are effective reduction preventers and may be used in any of the methods suggested in the examples above 2,4-dinitro phenol.

2,4-dinitro benzoic acid.

3,5-dinitro benzoic acid.

2,4-dinitro phenyl acetic acid.

3,5-dinitro salicylic acid.

2,6-dinitro 4-chlor phenol.

2,6-dinitro a-hydroxy benzene sulphonic acid.

2,4-dinitro toluene sulphonic acid.

ZA-dinitro 1-naphthol 7-sulphonic acid.

2,4-dinitro benzene sulphonic acid.

The phenolic bodies, in dilute alkali, form the sodium phenolates and the acids, of course, form the sodium salt.

The term coloring as used in the appended claims is intended to mean dyeing or printing with the dyestuffs as described.

It is to be understood that I am not limiting myself to the specific examples cited as to materials used, condition of operation, etc. since various modifications will suggest themselves to one versed in the art but that I am limited only as indicated in the claims which follow:

I claim:

1. In the processing of textiles the step comprising the application to textiles of sodium dinitro benzenesulfonate in the boiling off of fabrics containing vat dyed yarns.

2. The process of producing resists under vat dyestuffs comprising the steps of printing sodium di-nitro benzenesulfonate upon material, drying and subsequently coloring with a reduced vat dyestuff in the usual manner.

3. The process which comprises treating a dyed material with sodium di-nitro benzenesulfonate and subsequently printing with reduced vat dyestuffs in the usual manner.

4. The process which comprises treating warp yarns during sizing with sodium di-nitro benzenesulfonate and subsequently coloring with reduced vat dyestuffs in the usual manner.

5. In the processing of textiles the step which comprises the application of water soluble dinitro aryl derivatives to prevent the reduction of colors.

6. In the processing of textiles the step which comprises the application of water soluble dinitro benzene derivatives to prevent the reduction of colors.

7. In the processing of textiles the step which comprises the application of water soluble derivatives of aromatic dinitro compounds to prevent the reduction of colors.

8. In the processing of textiles the step which comprises the application of sodium di-nitro benzenesulfonate to prevent the reduction of colors.

DONALD H. POWERS. 

